Bacterial Flora of the Respiratory Tract
Even in healthy animals, a few bacteria of different species can be cultured from the respiratory system.
Clinical evaluations of the lower respiratory tract demonstrated that 35-50% of healthy dogs were culture-positive (11).
True primary pathogens of the lower respiratory tract, however, are viruses and bacteria, including Bordetella bronchiseptica, Mycoplasma, Streptococcus zooepidemicus and Mycobacteria, which are able to overcome respiratory defense mechanism and induce disease (11).
The majority of bacteria to be found in trachea and bronchial tree of healthy and diseased animals seems to be secondary opportunistic invaders, in most cases aspirated from the gastrointestinal tract, which take advantage of factors weakening the host defense system and become pathogenic.
References
| (11) |
King LG, Boothe DM: Bacterial infections of the respiratory tract in dogs and cats. Veterinary Learning Systems Kansas USA, 1997. | |
